Railway traffic controlling system



May 3, 1938.

w. T. POWELL.

RAILWAY TRAFFIC CONTROLLING SYSTEM Original Filed July 31, 1934 BY/ZMM ATTORNEY Patented May 3, 1938 UNITED STATES PATENT OFFIfiE RAILWAY TRAFFIC CONTROLLING SYSTEM Winfred T. Powell, Brighton, N. Y., assignor to General Railway Signal Company, Rochester,

4 Claims.

This invention relates to traffic controlling systems for railroads and it more particularly pertains to a system for the remote control of power operated switch machines.

This application is a division of my prior application Ser. No. 737,781, filed July 31, 1934, now U. S. Letters Patent No. 2,083,525.

In a system of remote control of power operated switch machines for use in connection with terminals, interlocking plants and centralized traflic controlling systems, it is desirable that the various controls and indications required for efiicient operation of a switch machine be obtained over a minimum number of line wires between the tower or control office and the remote point where the switch is located. Therefore, one object of the present invention is to provide a simple and reliable arrangement of line circuits and relays so organized that several different distinctive controlling conditions may be simultaneously transmitted in response to the energization or deenergization of the line circuits.

More specifically, this invention provides for the transmission of the controls required for a power operated switch machine over a single polarized line circuit and the provision in such a circuit of an improved arrangement for requiring the movement of the control lever at the time the locking is ineffective, in order to operate the switch machine in such a manner that it will not operate after a train movement over the switch until the operator shifts the control lever to its last previous effective position.

Briefly, an electric lock equivalent arrangement is provided whereby, in the event that the operator shifts the switch machine control lever while the circuits have the switch machine locked against operation, it is necessary for the operator to restore the switch machine control lever into correspondence with the position of the associated switch machine control relay before control of the switch machine is obtained, regardless of whether the switch machine remains locked or becomes unlocked in the interim.

Various other characteristic features and advantages of the invention will be in part apparent and in part specifically pointed out as the description thereof progresses.

In describing the invention in detail reference will be made to the accompanying drawing, which is a diagrammatic illustration of the present invention as applied to the control of a single track switch at a remote location.

Although the traflic controlling system of the present invention may be applied to various track layouts, involving conflicting and nonconflicting' routes and various other conditions encountered in practice, it has been specifically illustrated as applied to a single track switch and preferably associated with an automatic block signal system of the type, for example, as disclosed in the pend ing application of S. N. Wight, Ser. No. 120,423, filed July 23, 1926, now U. S. Letters Patent 2,082,436.

With reference to the accompanying drawing, the railroad track switch TS is illustrated as connecting the rails 3 of a main track to the rails 4 of a diverging or turnout track. Track switch TS is operated by a power driven switch machine SM, which may be of any suitable type such, for example, as disclosed in the patent to W. K. Howe, No. 1,466,903, issued September 4, 1923. This switch machine may be provided with a dual control selector to permit hand operation of the track switch such as shown, for example, in the patent to W. K. Howe, No. 1,852,576, issued April 5, 1932.

The main track adjacent the track switch TS and a portion of the diverging track to the fouling point, comprises a detector track circuit of the closed circuit type with the usual track battery 5 and track relay T, which detector track circuit is insulated from the rest of the track layout by the usual insulated joints.

Trafiic over the track switch in an east bound direction is governed by signals I and ID on the main track and on the turnout track respectively. Traffic over the track switch in a west bound direction is governed by signals 2 and 2D on the main track and off the turnout track respectively.

The track switch and the switch machine are preferably provided with point detector contacts of some suitable type such, for example, as disclosed in the patent to C. S. Bushnell, No. 1,517,236, issued November 25, 1924. These point detector contacts are employed to energize a switch position repeating relay of the usual polar neutral type, in accordance with the position and the locked or unlocked condition of the track switch, but since this particular feature forms no part of the present invention it has been omitted from the disclosure for the sake of simplicity.

Referring to the drawing, a polar relay WZ of the magnetic stick type is governed from the control ofiice over a suitable polarized line circuit, including line conductor WL and common conductor C. This relay may be of any suitable type, in which the polar contacts are operated to one extreme position or the other in response to current flow over the line circuit in a particular direction or another, the polar contacts remaining in their last actuated positions when the winding of the relay is deenergized.

Signal repeating relay M is provided to repeat the condition of the signals associated with the illustrated track section. This relay is energized as long as all signals are at stop and is deenergized when any one of the signals is clear. Since the method of providing this feature forms no part of the present invention and since it is well known to those skilled in the art, the operation of relay M is merely indicated by associating the relay with contacts ll, I2 and [3 of the associated signals by a dotted line to indicate that the relay is energized when all the signals are at stop.

Lock relay L is provided to lock the associated switch control circuit against operation whenever the track section is occupied or whenever a signal is clear. Such operation. is provided by deenergizing relay L to open the control line circuit extending to relay WZ.

Lock repeater relay LP is provided for the purpose of effecting the electric lock equivalent feature, as will be specifically pointed out. Resistance RS is for the purpose of maintaining a substantially uniform current flow through the upper winding of relay LP, whether this winding is energized locally by both portions of battery B or over the line circuit.

In the control ofiice, signal control lever SGL is illustrated to indicate that the signals at the remote point are controlled over signal control line conductor GL. Since this operation forms no part of the present invention, it is merely indicated by a dotted line, the detailed circuits being omitted. Switch machine control lever SML in the control oflice is for the purpose of controlling the associated switch machine, the detailed operation of which will be explained later.

Battery B in the control office and battery B at the field station are each provided with a center tap (CN), with these center taps being connected together by means of common conductor C. The symbol (B+) is associated with the terminal of each of these midtap batteries and symbol (B) is associated with the terminal of each battery, it being understood that current flows from the (B+) terminal in the external circuit back to the midtap or the (B) terminal as determined by the circuit connections. To simplify the illustration, the symbol is used to indicate the positive terminal and the symbol is used to indicate the negative terminal of a suitable battery or other source of current at the station, with the circuits to which these terminals are connected having current flowing in the external circuit from to It is believed that further description of the present invention will best set forth the characteristic features and functions of the system, by considering the detailed operation under certain characteristic or typical conditions.

Operation Normal condition.With the detector track section unoccupied and with the switch control lever SML in the position illustrated, the various devices, relays and circuits assume positions and conditions of energization as illustrated. Since it is assumed that the track section is unoccupied, track relay T is normally energized and since all signals are at stop, relay M is normally energized. With relays M and T energized a circuit is closed for energizing relay L which extends from front contact 1 of relay M, front contact 6 of relay T and winding of relay L, to

Relay LP is energized over a stick circuit ex tending from the (B+) terminal of battery B front contact 25 of relay L, resistance RS, front contact 26 of relay LP and upper winding of relay LP, to the (B) terminal of battery B The energizing current for the upper winding of relay LP is maintained at a normal level, when both portions of battery B are connected to the circuit, by means of resistance RS.

Relay WZ is energized over a circuit extending from the (B+) terminal of battery B in the control office, lever SML in its normal position, line WL, front contact 2| of relay LP, front contact 20 of relay L, winding of relay WZ and common conductor C, to the (CN) terminal of battery B, which is the terminal of the right hand portion of this battery. Contact In of relay WZ, in its right hand normal position, controls the normal operating circuit of switch machine SM and contact H1 in its left hand reverse position controls. the reverse operating circuit of switch machine SM, as indicated by reference characters N and R M anaal control of track switch-It will now be assumed that the operator moves lever SML to, its reverse dotted line position. The actuation of lever SML to its reverse position closes a circuit from the (B) of battery B, contact of lever SML in its reverse position R, line conductor WL, front contacts 2| and 20 of relays LP and L respectively, winding of relay WZ and conductor C, to (CN). The reversal of current over the line circuit switches the polar contacts of relay WZ from their right hand normal positions to their left hand reverse positions and contact I0 governs the operation of the switch machine to its reverse position.

The operation involved in actuating the track switch from its reverse position to its normal position is merely the reverse of that described and need not be specifically pointed out. It need only be mentioned that the return of lever SML to its normal position reverses the current flow through relay WZ for positioning the polar contacts of this relay back to their right hand normal positions.

Manual control of signals.Assurning clear traffic conditions, either signal I or 2 may be cleared with the track switch in a normal position and signal ID or 2D may be cleared with the track switch in a reverse position. The signals are governed in accordance with the position of signal lever SGL and, as above mentioned, the detailed circuits for clearing the signals are not shown. It will be understood that the series circuit including relay M is opened when any signal is cleared, due to the opening of some one of the contacts ll, 12 or I3.

The deenergization of relay M opens the energizing circuit of relay L at front contact I, causing relay L to be deenergized. The opening of front contact 20 of relay L locks the switch control circuits, so that the operator does not have control over relay WZ during the time that a signal, governing traffic over the track switch, is clear.

An electric bias control feature is provided to maintain relay WZ energized in its last energized condition when relay L is dropped. For example, with the circuits in the conditions shown, the dropping of relay L closes a circuit for maintaining relay WZ energized in the same direction,

which circuit extends fromthe (B+) terminal of battery B contact 22 of relay WZ in its right hand position, back contact 20 of relay L and winding of relay WZ, to (ON) It will be obvious that if relay WZ has its contacts in their left hand position, due to lever SML being actuated to its reverse position, then the release of relay L completes a circuit for maintaining relay WZ energized, from the (B) terminal of battery B contact 22 of relay WZ in'its left hand dotted position, back contact 20 of relay L and winding of relay WZ, to (CN) Electric lock equioale'nt.In the event that the operator actuates lever SML to a new position while the track switch is looked, as indicated by relay L being deenergized, this actuation is ineffective to condition the control circuits. With the circuits in the conditions indicated, it will be assumed that relay L is deenergized and that the operator actuates lever SML to its reverse position before relay L is picked up. It will be understood that relay L will be dropped by deenergizing its circuit in response to the clearing of a signal or in response to the occupancy of the track section, as above described. Since the control line circuit WL is open at front contact 20 of relay L, the actuation of lever SML is ineffective to energize relay WZ.

The deenergization of relay L opens the above described stick circuit of relay LP at front contact 25, so that relay LP is released. Under this condition, the actuation of lever SML is ineffective because the WL line circuit is open at front contact 2i of relay LP and at front contact 24 of relay L, both relays being deenergized.

When relay L is again picked up, then if lever SML is in its normal position a circuit is closed for picking up relay LP which extends from (B+) contact of lever SML in its normal position, conductor WL, back contact 2| of relay LP, front contact 26 of relay L, contact 23 of relay WZ in its right hand normal position, upper winding of relay LP, through the right hand portion of battery B and conductor C, to the (CN) terminal of battery B. It will be noticed that the right hand portions of batteries B and B are connected in series aiding relation in the above described circuit, so that relay LP is energized. The closure of front contact 26 of relay LP completes the stick circuit for this relay before the above described pick up circuit is broken at back contact 2|. This is due to the fact that front contact 26 closes before back contact 2| opens. This stick circuit extends from the (B+) terminal of battery B front contact 25 of relay L, resistance RS, front contact 26 of relay LP and upper winding of relay LP, to the (B) terminal of battery B A similar condition exists with relay WZ in its left hand reverse position, when relay L is picked up after being deenergized. Under this condition a circuit is closed for energizing relay LP which extends from the (B) terminal of battery B, contact of lever SML in its reverse dotted line position, conductor WL, back contact 2! of relay LP, front contact 24 of relay L, contact 23 of relay WZ in its left hand dotted position, lower winding of relay LP, through the left hand portion of battery B and conductor C, to the (CN) terminal of battery B. Relay LP again picks up and closes its above described stick circuit.

In the event that lever SML is actuated out of correspondence with relay WZ when relay L is deenergized, then upon the picking up of relay L, relay LP cannot be energized because like terminals of the batteries are connected to opposite terminals of the windings of relay LP. For ex ample, with lever SML in its normal position and relay WZ in its reverse position, a circuit may be traced from the (B+) terminal of battery B, contact of lever SML in its normal position, conductor WL, back contact 2| of relay LP, front contact 24 of relay L, contact 23 of relay WZ in itsleft hand dotted position and lower winding of relay LP, to the (B+) terminal of battery B which circuit is not energized and will not pick up the LP relay.

Or if lever SML is in its reverse dotted line position when relay W2 is in its normal position, then a circuit may be traced from the (B-) terminal of battery B, contact of lever SML in its reverse dotted position, conductor WL, back contact 2| of relay LP, front contact 24 of relay L, contact 23 of relay WZ in its right hand normal position and upper winding of relay LP, to the (B) terminal of battery 13 Current does not flow in this circuit because like terminals of both batteries are connected to opposite terminals of the relay winding and the relay will not be picked up. It therefore becomes necessary for the operator to restore lever SML to the position it previously occupied when the last effective control was exercised over the switch control circuits, before control of these circuits can again be obtained.

It is to be understood that, although only one specific embodiment of the present invention has been disclosed, the principles of the invention may be applied to various other types of systems and various types of track layouts may be controlled in a similar manner, without departing from the spirit of the present invention. The present disclosure has been chosen merely for providing a simplified showing which could be clearly described in the specification.

Having described a traffic controlling system for one specific embodiment of the present invention, it is desired to be understood that the form is selected to facilitate in the disclosure rather than to limit the number of forms which it may assume and it is to be further understood that various modifications, adaptations and alterations may be applied to the specific form shown in order to meet the requirements of practice, all without in any manner departing from the spirit or scope of the present invention except as limited by the appended claims.

What I claim is:-

1. In a system of control for power operated track switches for railroads; a switch machine for operating a track switch; a source of energy at said switch machine; a polar relay at said switch machine for controlling it to normal and reverse positions; a switch machine control lever and a source of energy at a control oflice; a normally energized lock relay associated with said switch machine and deenergized whenever it is unsafe,

to operate said track switch; a lock repeating relay; a control circuit for said polar relay including a front contact of said lock repeating relay and energized with current of one polarity or the other from said control ofiice source of energy in accordance with the position of said switch machine control lever; pick-up circuit means for said lock repeating relay including a front contact of said lock relay and both said control oflice source of energy and said source of energy at said switch machine, said pick-up circuit having current flow therein only when said control office source of energy is connected into said circuit by said switch machine control lever in an aiding relationship to said source of energy at said switch machine as it is then connected in the circuit by said polar relay; and stick circuit means for said lock repeating relay including a front contact of said lock relay and its own front contact, said stick circuit means when once energized remaining energized dependent upon said lock relay irrespective of correspondence between said switch machine control lever and said two-position polar relay.

2. In a remote control system for power-operated track switches; a power-operated switch machine; a source of energy at said switch machine having terminals of opposite polarity and a mid-tap; a polar relay for controlling said switch machine and having one terminal connected to the mid-tap of said source of energy at said switch machine; a switch machine control lever at a control ofiice; a source of energy at said control ofiice having terminals of opposite polarity and a mid-tap; a lock relay associated with said track switch and energized except when it is unsafe to operate said track switch; a lock repeating relay having two windings; a common line wire connecting the mid-tap of said control oifice source of energy and the mid-tap of said source of energy at said switch machine; a control line wire extending between the control ofiice and said switch machine and connected to one terminal or the other of said control oflice source of energy in accordance with the position of said switch machine control lever, said control line wire at the switch machine being connected to said polar relay through a front contact of said lock repeating relay; circuit means connecting the two windings of said lock repeating relay to the opposite terminals of said source of energy at said switch machine; circuit means connecting the other terminal of one of said windings of said lock repeating relay through a circuit including a contact closed with said polar relay in, one position and a front contact of said lock relay to said control line wire, and connecting the other terminal of the other winding of said lock repeating relay through a circuit including a polar contact of said polar relay in its other position and a front contact of said lock relay to said control line wire, whereby said lock repeating relay is energized with a potential of said control oflice source in an aiding relation to a potential from said switch machine source of energy when said switch machine control lever and said polar relay are in corresponding positions; and stick circuit means for said lock repeating relay for energizing said lock repeating relay when once picked up dependent only upon the picked up condition of said lock relay.

3. In a system of control for power-operated track switches for railroads; a switch machine; a switch control polar relay for governing the operation of said switch machine to the normal or reverse position; a source of energy and a control lever at a distant control office; a control circuit for energizing said switch control relay with one polarity or the other from said control oflice source in accordance with the position of said lever; a lock relay adjacent the switch machine automatically deenergized when the switch machine operation should be prevented; means rendered effective upon deenergization of said lock relay to open said control circuit and to maintain it open until said means is restored; a source of energy at the switch machine, and a restoring circuit for said means including a contact closed only if said lock relay is energized, said source of energy in the control ofiice and contacts of said lever; said source of energy at the switch machine and polar contacts of said switch control relay, said restoring circuit having current flowing therein only if said lever and said polar contacts are in corresponding positions so that said sources of current act cumulatively.

4. In a system of control for power-operated track switches for railroads, a switch machine, a switch control polar relay adjacent the switch machine for governing its operation to the normal or the reverse position, a control lever and a battery at a distant control office, a control circuit including a line wire for energizing said switch control relay with one polarity or the other in accordance with the position of said lever, a lock relay deenergized whenever operation of the switch machine should be prevented, a stick relay adjacent the switch deenergized whenever said lock relay is deenergized for opening said line wire of said control circuit and to maintain such opening until said stick relay is restored, a local battery at the switch machine, and means including said line wire for restoring said stick relay only if the battery in the control office is connected to said line circuit by said lever with a polarity to act cumulatively with the battery at the switch machine as connected to said line wire by a polar contact of said switch control relay.

W'INFRED T. POWELL. 

